Insulation for oil tanks



Octl 20,

L. A. BALDWIN INSULATION FOR OIL TANKS Filed June l, 1923 5 Sheets-Sheet 1 Alim in.,

Oct 20' L. A. BALDWIN INSULATION FOR OIL TANKS V1923 3 Sheets-Sheet 2 Filed June l Oct. 20l 1925. N 558,217

L. A. BALDWIN INSULATION FOR OIL TANKS Filed June l, 1923 3 Sheets-Sheet 5 Patented Oct. 20, 1925.

UNITED STATES 1,558,217 PATENT OFFICE.

LESLIE A. BALDWIN, OF ST. LOUIS, MISSOURI, ASSIGNOR TO JOHNS-MANVILLEfINC., A CORPORATION OF NEW YORK. I

INSULATION FOR OIL TANKS.

Application` led June 1,

To all lwhom t'mag/ concern.'

V a citizen of the United States, residing at tanks with conical or domed roofs.

St. Louis, in the State of Missouri, havejinvented certain new and useful. Improvements in Insulation for Oil Tanks, of which the following is a specification.

This invention relates to storage and like tanks for crude oil, petroleum fractions and the like, and particularly to an insulated tank designed to minimize the evaporation of the lighter and more valuable fractions which are lost in large quantities under present methods of storage.

The present method of refining and storing crude oil and other petroleum products involves storage in vertical cylindrical steel These roofs close the tops of the tanks tightly' eX- cept for vents which extend through the roofs and are equipped with goosenecks to secure reasonable isolation of the space above the liquid in the tank from the outside air.

Evaporative losses from tanks of this de-y scription are larger`than fwould be supposed from a casual consideration of the subject. The tanks are bare and their side walls be come heated by the sun through the day. The resulting convection currents in,tl1e oil carry this heat throughout the tank. Furthermore 4these currents carry all parts of the liquid to the surface, and the joint effect of the heat and circulation is accelerated evaporation and selective evaporation of the more volatile constituents. Furthermore the wide range between night and day temperatures causes alternating expansions and contractions of the air and vapors above the liquid in the tank, with alternating outiiow of vapor-saturated air and inflow of unsaturated air.- YThis breathing of the 1923. Serial No. 642,843.

inexpensive commercial materials and be suited to exposure to the weather.

Preferred embodiments of the invention are illustrated in the accompanying drawings, in which Fig. 1 is a perspective view of a portion of the side Walls and roof of a tank insul lated according to this invention, but with various layers of insulation partly broken away to show how the material is supported and arran ed.

Fig. 2 1s a fragmentary section at the` apex of the roof showing the mode of con-l necting the stay wires over the first layer of insulation in the structure of Fig. 1.

Fig. 3 is a view similar to Fig. 2 showing how angle irons or 'angle iron clips may be substituted for the stay wires.

Fig. 4 is a vertical section through a portion of the side wall and roof of the tank shown in Fig. 1.

Fig. 5 is a iview similar to Fig. 1 showing a modified construction in which an le irons are substituted for the circum erential cables.

Referring first to Figs. 1 and 4, the side wall of the tank is indicated at 11, the bottom at 12 and the nconical roof at 13. An angle iron 14 surrounds the upper margin of the side walls 11 and serves as a means to connect the roof and side walls which are riveted to it as indicated at 15 and 16 respectively. No attempt has been made to illustrate any =of the internal supporting tframework such as columns, rafters, roof purlins and the like, as such features are familial' and the present, invention is not concerned with them.

A series of galvanized stranded cables 17 are drawn taut around the tank in such positions that they are supported by the overlapping edge of the plates at the joints, or by the projecting rivetV heads, the former being preferred where available. tightening is done by means'o turn-buckles 18. The cables 17 are. further supported by heavy ,vertical galvanized suspender Wires 19 spaced about five feet on centers and supported at their upper ends by the cable 17 under angle iron 14. This top cable 17 is supportedby the wire 28, Figs. 1 and 4, vstretched radially from cable loop 27 in Fig. 2 or a convenient mode of connecting the wires is to remove certain of The final the rivets 15 and loop the wire through the rivet hole as is indicated at 5 in Fig. 1.

The vertical wires 19 and the cables 17 may be connected 'in any desired way, but Ir prefer and illustrate the use of ties 21 made of galvanized annealed wire. These ties 21 are looped over and under so as to lock the cable in a bight of the suspender wire, and are then twisted suilciently to lretain the connection. Their ends are thereafter bent so as to project radially outward from the tank wall to pierce the first layer of insulation. This insulation layer is indicated at 22 and may advisably consist of hair felt, or better a well known commercial type consisting of hair flt with a layerl of waterproof paper on one or both sides. This layer of insulation, whatever its specific form, is mo ped onJJ with hot roofing as# phalt 10 so t at the asphalt forms an adhesive bond between the tank wall and the layer of insulating felt. As the felt is put in place, the tie w1res 21 are pushed through it and are later used to bin light circumferential cables 23 drawn taut around the felt. The cables 23 are supported by la second set of 4suspender wires 24 similar to the wires 19,v and sup orted by top cable 17. The joints between t e cables 23 and suspender wires 24 are .made by ties 25 similar to the ties 21, but preferably/ distinct therefrom and staggered relatively thereto, so as to lengthen the path for heat through these metal connections. y

A second layer of insulating felt 26 is then applied and is caused to adhere to the first by the use of hotf roofing asphalt. The tie wires 25 pass through thls layer and are used to support Ametal lath or -urring, as

will be later described. A .second set of light circumferential cables 8 is 'then applied,

icient. Additional layers may be applied in the same way if necessary.

The first layer of insulating, felt 31 'is mtpped to the roof 13 with hot asphalt 10 A nor extended ,over the eaves and down into contact with the similar felt on the side walls. The downward rojecting layers are skived or beveledas c early shown in the drawin and the first layer 31 lashed by circum erential stranded cablesf33. :After this first la er ,31 has.been mopjad on, a ring or loop o heavy galvanizedfca le 27, Fig. 2, is placed over this insulation at top point of roof. This loop oers support to a series of' wires 28jextending in. at radial direction to theeaves of the roo and there connecting to the' topmost cable 17 as a means of support for that cable and also to hold"down the first layer of insulatingfelt 31.

v These wires 28 also oier connection :jj-to Two layers of felt are ordinarily suftie wires 29 which hold down the second layer of insulating felt on roof and the furring. In many cases it may be preferable to substitute radially extendinr angle irons 30, Fig. 3, riveted to the roof deck or angle iron clips 30, 3, welded on to roof deck, Tie wires 29, ig. 3, are attached to the angles or4 angle clips.

A second layer of insulating felt 32, Figs. 1y and 4, is mopped over the first felt 31 with hotA asphalt 10. Tie wires 29 are brought through this felt and it is extended over eaves as before and lashed with cables 34. Between radial cables 28 vand 20, Fig.

1, light cables 6 and 7 are laced both to hold down layers of insulating felt and to supwhich extend radially from the apex of the roof, over the eaves and vertically down the sides. For this purpose, I prefer a metal lath of the expanded metal type having integral channel-shaped stiffening ribs of unslitted `metal. The commercial material known as hy-rib is typical, but the exact form of the furring is not a feature of the invention. This urring is fastened in place by means of the tire wires 25 and 29,. asD

shown in Figs. 1 and 4.

Over the metal lath or furring 35 are troweled 'two coats of asbestos cement, indicated at 36 and 37,- the outer one of these two coats at least being composed` of water proof material.

' Over the roof portion and around the eaves, a multiple-ply asbestos rooiing 38 is applied. This is caused. to adhere by mop!l plug it on with hot roofing asphalt, and it is retainedin position by a la er of galvanized iron mesh wire 39 Whic cable 40 extending around the tank and its insulation a short distance below theA eaves.

Thewholel is then given a final weatherproof coating 41 which may consi.. Lof h ot roofing asphalt mopped posed of any other desirable weather-iesisting material.

` In order to prevent the absorption` of moisture by' the heat insulatingr layers-on the tank,the insulatin materia terminates above the ground leve as indicated at 42,

Fig. 4,l andis protected by a flashing strip 430i asphalt saturated fabric, asbestos felts overlies the-4 4entire roof of the tank, `and which is conh nected at its lower edge to a circumferential on, or mayy be AcolnorI other waterproofing e felts which are mopped to the walls of the tank with hot asphalt for a substantial distance above the ground, across the bottom of the two layers of insulating felts and up the outside of last layer of insulating felt for as great a 'distance as it was mopped on side walls of tank. Either a concrete curb 44, Fig. 4, is vinstalled around the bottom of tank or the space between bottom of insulation and the ground is filled with fine gravel to insure a good drainage.

In Fig. 5 is shown an alternative construction in which l dispense with the circumfere-ntial cables 17 and substitute therefor circumferential angle irons 45 welded in place. These proect through the first layer of insulating felt 22 and hence support this layer which, as in the construction first described. is retained byfcircuniferential cables 23 having suspender Wires 24 and secondary tie wires 25.

y ring strip supports two successive layers of asbestos cement 4S and 49, just as in the structure previously described.

As illustrating an alternative final finish, I show in Fig. 5 the application over the second coat 49 of asbestos cement of a coat 50 of concrete primer followed by a coat 5l of fibrous enamel. The exact nature of these final coats is not material it is possible to use any coating material which is weatherproof, and which has a good bonding effect on the surface so asvto'reduce any tendency to chip or crack.

The various forms of the invention above described have many features in common. They involvethe use of thick sheet insulating n'iaterial near the wall of the iank with a coating or shell of asbestos heat insulating cement. Any such insulating shell requires support and the method'described, in which the layers are supported by tie members connected to the tank or to elements supported by the tank, provides a simple construction which may be used Aon existing tanks, or on existing types of tank, without y requiring any radical structural modifica- 'J- materially from past standard practice.

1. The combination with an oil tank of f a plurality of tie wires supported by the .walls of said tank and extending outward therefrom; sheet insulation arranged in one or more layers pierced by said tie wires andy surrounding said tank; metal lath overlying said sheet insulation and held in place by said tie wires; and hardened plastic heat insulating material overlying and supported by said lath.

2. The combination with an oil tank including side walls and a roof of a plurality of tie wires supported by said Walls and roof and extending outward therefrom; sheet insulation pierced by said tie wires and arranged in one or more layers, on said .side Walls and roof, that sheet insulation on the roofbeing folded around the eaves to overlap the upper portion of that on the side walls; metal lath, said lath overlying said sheet insulation and being fixed in place by said tie Wires; and hardened plastic heat insulating material overlying and supported by said lath.

3. The combination with an oil tank including side Walls and a roof of a plurality of tie wires supported by said walls and roof and extending outward therefrom: sheet insulation pierced by said tie wires and arranged in one or more layers, on said side walls and roof, that sheet insulation on the roof being folded around'the eaves to overlap lthe upper portion of that on the side walls; metal lath arranged in strips extending radially from the tenter of the roof t the eaves and thendown the side walls, said ing fixed in place bysaid tie Wires; and

lhardened plastic heaty insulating material overlying andsupported by said lath.

4. The combination with an oil tank including side walls and a roof of a plurality of'tiewires supported by said walls and roof and extendingoutward therefrom; sheet insulation pierced by said tief wires and arranged in one or more layersgon said side Walls and roof, that sheet insulation on the roof being folded around the eaves to overlap the upper portion of that on the side Walls; metal lath, said lath overlying said sheet insulation and being :fixed in place by said tie Wires; hardened plastic heat insulating material overlying, and supported by said lath; and a ,water-proof roofing of sheet material overl ing the roof and eaves portion of said har ened plastic heat insulating material.

5. The combination with an oil tank of a pluralit of cables stretched taut around said tan and supported by engagement with surface irregularities of the tank; a lurality of tie wires connected with said ca les and extending outward from the surface of the tank; sheet insulation arranged in one or more layers and pierced by said -tie wires;

a second set of tie wires carried by said circumferential cables; a second layer of sheet insulation overlying the first and pierced by the second set of tie wires; metal lath overlying the second layer of insulation and retained by the second set of tie wires; and plastic heat insulating material overlying and supported by said lath.

7. The combination of a roofed cylindrical oil tank; a plurality of cables stretched Vtaut around the side walls of said tank and supported by engagement therewith; a plurality of tie wires connected with said cables and extending outward from the surface of said tank; a plurality of tie wires supported by the roof and` extending upward Y therefrom; a plurality of layers of sheet insulating material covering said' side walls and roof and pierced by tie wires, those on the roof extending downward around the eaves and overlapping'the upper portionof those on the side Walls; circumferential binding cables certain of which surround layers of side wall insulation and are connected witli adjacent tie wires, and certain others of which surroundy and bind the down-turned margins of the roof insulation; secondary tie wires 'supported by said cables; lath overlying said roof and side wall insulation and retalned by said roof tie wires and said secondary tie wires; and a coating of hard.- ened plastic heat .insulating material covering and supported by said lath.

8. The combination of a roofed cylindrical oil tank; a plurality of cables stretched 'by the roof and extending upwar taut around the side walls of said tank and supported by engagement therewith; a plurality of tie wires connected with said cables and extending outward from the surface -of said tank; a plurality of tie wires su pported therefrom; a plurality of layers of sheet insulating material covering said side Walls and roof and pierced by tie wires, those on the roof extending downward around the eaves and overlappin the upper portion of those on the side wa ls; circumferential binding cables certain of which surround layers of side wall insulation and are connected with adjacent tie Wires, and certain others of which surround and bind the downturned margins of the roof insulation; secondary tie wires supported by said cables; lath overl lying said roof andside wall insulation and retained by said roof tie wires and said secondary tie wires; a coating of hardened plastic heat insulating material covering and supported by said lath; and a multiple-ply sheet roofing applied over the roof portion" of said hardened plastic material.

9. The combination of a roofed cylindrical oil tank; a plurality of cables stretched taut around the side walls of said tank and supported by engagement therewith; a plurality of tie wires connected withsaid cables and extending outward from the surface of said tank; a plurality of tie wires supported by the roof Land extending upward therefrom; a plurality of layers of sheet insulating material covering said side walls and roof and pierced by tie wires, those on the roof extending downward around the eaves and overlapping the upper portion of those on the side walls; 3circumferential binding cables certain of which surround layers of side wall insulation and are connected with adjacent tie wires, and certain others of which surround and bind the downturned margins of the roof insulation; secondary tie wires supported by said cables; lath overqlying said roof and said side wall'insnlation and retained by said roof tie Wires and said secondary tiev wires; a coating of hardened plastic heat insulating material covering and suptpprted by said lath; a multiple-ply sheet roo g applied over the roof portion of said hardened plastic materiali; a wire mesh fabric stretched over said roofing to retain and protect the same; and a binding cable connected to the margin of said fabric and drawn ,taut about the insulatingI layers on the lside walls of said tank.

, In testimony whereof I have signed my name to this specification. v

LEsLiE A.' BALDWIN. 

